Java code manually Triggering kubernetes cronjob from the cluster-CodePudding

I'm trying to trigger cronjob manually(not scheduled) using fabric8 library but getting the following error:

Caused by: io.fabric8.kubernetes.client.KubernetesClientException: Failure executing: POST at: https://172.20.0.1:443/apis/batch/v1/
namespaces/engineering/jobs. Message: Job.batch "app-chat-manual-947171" is invalid: spec.template.spec.containers[0].name: Re
quired value. Received status: Status(apiVersion=v1, code=422, details=StatusDetails(causes=[StatusCause(field=spec.template.spec.co
ntainers[0].name, message=Required value, reason=FieldValueRequired, additionalProperties={})], group=batch, kind=Job, name=ap
p-chat-manual-947171, retryAfterSeconds=null, uid=null, additionalProperties={}), kind=Status, message=Job.batch "app-chat-man
ual-947171" is invalid: spec.template.spec.containers[0].name: Required value, metadata=ListMeta(_continue=null, remainingItemCount=
null, resourceVersion=null, selfLink=null, additionalProperties={}), reason=Invalid, status=Failure, additionalProperties={}).

my code is running at the cluster:

maven dependency:

<dependency>
            <groupId>io.fabric8</groupId>
            <artifactId>kubernetes-client</artifactId>
            <version>6.3.1</version>
</dependency>

java code:

public static void triggerCronjob(String cronjobName, String applicableNamespace) {
        KubernetesClient kubernetesClient = new KubernetesClientBuilder().build();

        final String podName = String.format("%s-manual-%s", cronjobName.length() > 38 ? cronjobName.substring(0, 38) : cronjobName,
                new Random().nextInt(999999));

        System.out.println("triggerCronjob method invoked, applicableNamespace: "   applicableNamespace
                  ", cronjobName: "   cronjobName   ", podName: "   podName);

        Job job = new JobBuilder()
                .withApiVersion("batch/v1")
                .withNewMetadata()
                .withName(podName)
                .endMetadata()
                .withNewSpec()
                .withBackoffLimit(4)
                .withNewTemplate()
                .withNewSpec()
                .addNewContainer()
                .withName(podName)
                .withImage("perl")
                .withCommand("perl", "-Mbignum=bpi", "-wle", "print bpi(2000)")
                .endContainer()
                .withRestartPolicy("Never")
                .endSpec()
                .endTemplate()
                .endSpec().build();

        kubernetesClient.batch().v1().jobs().inNamespace(applicableNamespace).createOrReplace(job);
        kubernetesClient.close();
        System.out.println("CronJob triggered: applicableNamespace: "   applicableNamespace   ", cronjob name: "   cronjobName);
    }

the code executed at the kubernetes cluster, but not form the application, it's an external program that's running in the cluster.

my goal is to trigger given job in a given namespace.

CodePudding user response：

The error message is indicating that the Kubernetes API is returning a status code of 422, which is indicating that the Job object you are trying to create is invalid. Specifically, it is saying that the "spec.template.spec.containers[0].name" field is required but is not present in the Job object you are trying to create.

You can try adding a container name while creating JobBuilder object like this:

.addNewContainer()
.withName("container-name")
.withImage("perl")
.withCommand("perl", "-Mbignum=bpi", "-wle", "print bpi(2000)")
.endContainer()

This should fix the issue.

CodePudding user response：

If you want to trigger an already existing CronJob, you need to provide ownerReference for the existing CronJob in Job:

// Get already existing CronJob
CronJob cronJob = kubernetesClient.batch().v1()
       .cronjobs()
       .inNamespace(namespace)
       .withName(cronJobName)
       .get();

// Create new Job object referencing CronJob
Job newJobToCreate = new JobBuilder()
       .withNewMetadata()
       .withName(jobName)
       .addNewOwnerReference()
       .withApiVersion("batch/v1")
       .withKind("CronJob")
       .withName(cronJob.getMetadata().getName())
       .withUid(cronJob.getMetadata().getUid())
       .endOwnerReference()
       .addToAnnotations("cronjob.kubernetes.io/instantiate", "manual")
       .endMetadata()
       .withSpec(cronJob.getSpec().getJobTemplate().getSpec())
       .build();
// Apply job object to Kubernetes Cluster
kubernetesClient.batch().v1()
       .jobs()
       .inNamespace(namespace)
       .resource(newJobToCreate)
       .create();